Grinding media wear and its effect on the flotation of sulfide minerals

Abstract

Grinding in steel mills adversely affects the flotation of pyrrhotite. Rest potential and galvanic current measurements were made to study the electrochemical interactions between pyrrhotite and several metal electrodes including mild steel, austenitic and martensitic stainless steels, zinc and magnesium. Adverse effect on its floatability was most pronounced when pyrrhotite was contacted with magnesium and least when the sulfide mineral was contacted with austenitic stainless steel. Auger electron spectroscopy and X-ray photoelectron spectroscopy indicated that galvanic coupling of pyrrhotite with active metals resulted in the formation of hydroxide or oxide and sulfate species of iron on the pyrrhotite surface.